@@ -15,14 +15,15 @@ Common events are classified into system common events and custom common events.
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@@ -15,14 +15,15 @@ Common events are classified into system common events and custom common events.
Common events are also classified into unordered, ordered, and sticky common events.
Common events are also classified into unordered, ordered, and sticky common events.
- Unordered common events: common events that CES forwards based on the subscription sequence, regardless of whether subscribers receive the events.
- Unordered common events: common events that CES forwards regardless of whether subscribers receive the events and when they subscribe to the events.
- Ordered common events: common events that CES forwards based on the subscriber priority. CES forwards common events to the subscriber with lower priority only after receiving a reply from the previous subscriber with higher priority.
- Ordered common events: common events that CES forwards based on the subscriber priority. CES forwards common events to the subscriber with lower priority only after receiving a reply from the previous subscriber with higher priority. Subscribers with the same priority receive common events in a random order.
- Sticky common events: common events that can be sent to a subscriber before they initiate a subscription. Only system applications and system services can send sticky common events, and they must request the **ohos.permission.COMMONEVENT_STICKY** permission. For details about the configuration, see [Permission Application Guide](../security/accesstoken-guidelines.md#declaring-permissions-in-the-configuration-file).
- Sticky common events: common events that can be sent to a subscriber before or after they initiate a subscription. Only system applications and system services can send sticky common events, which remain in the system after being sent. The sends must first request the **ohos.permission.COMMONEVENT_STICKY** permission. For details about the configuration, see [Permission Application Guide](../security/accesstoken-guidelines.md#declaring-permissions-in-the-configuration-file).
Each application can subscribe to common events as required. After your application subscribes to a common event, the system sends it to your application every time the event is published. Such an event may be published by the system, other applications, or your own application.
Each application can subscribe to common events as required. After your application subscribes to a common event, the system sends it to your application every time the event is published. Such an event may be published by the system, other applications, or your own application.
